At present, a liquid crystal display device as being the display component of the electronic device has been widely applied in various kinds of electronic products. With the lightening development of the electronic products, the thickness of the liquid crystal display device becomes smaller and smaller, too. The backlight module is an important component in the liquid crystal display device.
In prior art, along with that the development of the liquid crystal TVs is directed toward large scale and high color saturation, for achieving better color saturation of the displays, and letting the people to sense abundant visual experience, laser light sources are introduced as being a kind of backlight source in the backlight of the liquid crystal display in recent years. In present laser backlight sources, mainly, the blue chip+green light phosphor LED (i.e. B+G phosphor LED) is utilized. With such back light in cooperation with a normal liquid crystal display screen, the color gamut is generally smaller than 100% NTSC color gamut. For reaching higher colorful expression and realizing higher color cover area, some has tried to utilize RGB three color lasers for attempting the achievement of high color saturation. However, the cost the RGB three color lasers is high, and the color is not easy to control. The color shift can easily occur.